Traditional, the anthropological definition of a religion is essentially a school of thought or philosophy that deals with the afterlife... though this leave confucionism flapping in the breeze. Scholarly sorts in Japan certainly, and presumably China consider Confucionism to be 'religious', though it is more of a 'way of life' than anything else.
Yes, I said Japanese. Yes, I know Confucious was Chinese. I have to go with my sources.